公开(公告)号：US3983488A

公开(公告)日：1976-09-28

申请号：US479808

申请日：1974-06-17

Applicant: John A. Bush ,  Drew R. Lance ,  John E. Altstatt

Inventor： John A. Bush ,  Drew R. Lance ,  John E. Altstatt

IPC: H03D3/00 ,  H03G3/34 ,  H04B1/10

CPC classification number: H03G3/345 ,  H03D3/002

Abstract: A threshold extension device for use in a frequency modulation demodulator circuit to minimize effects of impulse noise, usually referred to as "clicks", which normaly appear in the demodulated output signal, and including a delay line for delaying the demodulated signal, a follow and hold circuit for selectively omitting the click impulses from the delayed signal, a detector for detecting the occurrence of an event which will give rise to a click impulse in the demodulated signal, and a detector driven control signal generator for controlling operation of the follow and hold circuit.

Abstract translation: 一种用于频率调制解调器电路中的阈值扩展装置，用于最小化通常称为“咔嗒声​​”的脉冲噪声的影响，该正常值出现在解调输出信号中，并包括用于延迟解调信号的延迟线， 保持电路，用于选择性地从延迟信号中省略点击脉冲;检测器，用于检测将在解调信号中产生点击脉冲的事件的发生;以及检测器驱动的控制信号发生器，用于控制跟随和保持的操作 电路。

公开(公告)号：US3979679A

公开(公告)日：1976-09-07

申请号：US591533

申请日：1975-06-30

Applicant: John A. Bush ,  Drew R. Lance ,  John E. Altstatt

Inventor： John A. Bush ,  Drew R. Lance ,  John E. Altstatt

IPC: H03D3/00 ,  H03G3/34 ,  H04B1/10

CPC classification number: H03G3/344 ,  H03D3/001 ,  H04B1/10

Abstract: An improved squelch circuit for FM demodulators including a low pass filter for filtering out-of-band noise from the demodulator output signals, a delay line for time delaying the filtered signals, a gate for selectively passing the filtered demodulated output signals to an output terminal, and a control circuit for controlling the gate. The control circuit includes a high pass filter for passing the out-of-band noise in the demodulated signals, a detector for detecting the noise level of the noise passed by the high pass filter, and a comparator for comparing the detected out-of-band noise level to a reference to develop a gate control signal which causes the gate to be opened when the out-of-band noise level is relatively low and to be closed when the out-of-band noise level is relatively high.

Abstract translation: 一种用于FM解调器的改进的静噪电路，包括用于从解调器输出信号滤除带外噪声的低通滤波器，用于时间延迟滤波后的信号的延迟线，用于选择性地将滤波后的解调输出信号传送到输出端 ，以及用于控制栅极的控制电路。 控制电路包括用于在解调信号中传递带外噪声的高通滤波器，用于检测由高通滤波器通过的噪声的噪声电平的检测器，以及比较器， 带噪声电平作为参考，以产生门控制信号，当门带噪声电平相对较低时导致门断开，并且当带外噪声电平相对较高时闭合。

公开(公告)号：US4035736A

公开(公告)日：1977-07-12

申请号：US656534

申请日：1976-02-09

Applicant: Drew R. Lance ,  John E. Altstatt

Inventor： Drew R. Lance ,  John E. Altstatt

IPC: H03D3/24 ,  H03D3/00

CPC classification number: H03D3/241

Abstract: A low noise discriminator circuit having particular utility for use in determining the spectral purity characteristics of an rf signal source and comprising, in addition to standard discriminator components, a down-locked reference signal source including a voltage-controlled signal generator for developing a reference signal and a corresponding train of signal pulses, a stabilizing voltage-controlled oscillator which responds to the discriminator error signal and generates a stabilizing signal having a frequency at least an order of magnitude greater than the frequency of the reference signal, and a sampling phase detector which samples the stabilizing signal at the signal pulse frequency and develops a control signal which is fed through a feed-back loop to stabilize the reference signal generator.

Abstract translation: 一种具有用于确定射频信号源的频谱纯度特性的特别实用性的低噪声识别器电路，除了标准鉴别器组件之外，还包括一个下变频参考信号源，该参考信号源包括用于产生参考信号的电压控制信号发生器 以及相应的信号脉冲序列，稳定电压控制振荡器，其响应鉴别器误差信号并产生具有比参考信号的频率至少大一个数量级的频率的稳定信号;以及采样相位检测器， 以信号脉冲频率对稳定信号进行采样，并产生通过反馈回路馈送以稳定参考信号发生器的控制信号。